#![allow(dead_code, deprecated, unused_variables, unused_mut)]
#![feature(iter_map_windows)]
fn main() {
    let mut it = [0.5, 1.0, 3.5, 3.0, 8.5, 8.5, f32::NAN]
        .iter()
        .map_windows(|[a, b]| a <= b);
    assert_eq!(it.next(), Some(true));
    assert_eq!(it.next(), Some(true));
    assert_eq!(it.next(), Some(false));
    assert_eq!(it.next(), Some(true));
    assert_eq!(it.next(), Some(true));
    assert_eq!(it.next(), Some(false));
    assert_eq!(it.next(), None);
}